A. To enumerate the predominant flora in periodontal pockets of patients with periodontitis and juvenile periodontitis (periodontosis). B. To develop methods for rapid identification and enumeration of pocket organisms with pathogenic potential by immunofluorescence, cultural and functional procedures. C. To determine the antibiotic sensitivity of the predominant flora and of the potentially periodontopathologic flora in periodontal pockets as an aid in the selection of appropriate antibiotics for therapy. D. To monitor changes in pocket flora with therapy as part of longitudinal studies of effectiveness of therapy over a long period of time. E. To monitor development of antibiotic resistance in the oral flora during antibiotic therapy. F. To attempt to eradicate candidate pathogens from the periodontal microflora and to assess the clinical effects of this procedure. G. To carry out taxonomic studies including biochemical, serological, genetic and other procedures as necessary to classify periodontal pathogens.